A note on sample size savings with the use of a single well‐controlled clinical trial to support the efficacy of a new drug

In terms of the risk of making a Type I error in evaluating a null hypothesis of equality, requiring two independent confirmatory trials with two‐sided p‐values less than 0.05 is equivalent to requiring one confirmatory trial with two‐sided p‐value less than 0.001 25. Furthermore, the use of a single confirmatory trial is gaining acceptability, with discussion in both ICH E9 and a CPMP Points to Consider document. Given the growing acceptance of this approach, this note provides a formula for the sample size savings that are obtained with the single clinical trial approach depending on the levels of Type I and Type II errors chosen. For two replicate trials each powered at 90%, which corresponds to a single larger trial powered at 81%, an approximate 19% reduction in total sample size is achieved with the single trial approach. Alternatively, a single trial with the same sample size as the total sample size from two smaller trials will have much greater power. For example, in the case where two trials are each powered at 90% for two‐sided α=0.05 yielding an overall power of 81%, a single trial using two‐sided α=0.001 25 would have 91% power. Copyright © 2004 John Wiley & Sons, Ltd.     

Asian Transnational Families in New Zealand: Dynamics and Challenges

Since the 1990s, Asia has emerged as the major contributor of migration flows into New Zealand. Settler migration, tourism, international business and more recently, international education make up the diverse flows of Asian peoples into the country. This paper explores the changing dynamics of Asian transnational families over the last two decades, with a special focus on the experiences of young people within these families. In the early 1990s, bi-local families were commonly known as "astronaut" families, in which one or both parents returned to their countries of origin to work, leaving their children to be educated in New Zealand. Over time the structures of these families have changed, as many young migrants relocated back to their former homeland or re-migrated to a third country, while "astronaut parents" rejoined their spouses either in the origin or destination. More recently, the educational migration of international students from countries in Asia has given rise to another form of transnational family, in which young people enter New Zealand as international students and some subsequently become residents. In this paper, the experiences of these young people are explored within the wider context of family strategies for maximising benefits through spatially extended networks on the one hand, and government initiatives and immigration policy changes that have been taking place in New Zealand since the 1990s on the other.     

Top Team Diversity,Internationalization and the Mediating Effect of International Alliances*

This study examines the mediating effect of international alliances for the relationship between TMT (top management team) job‐related diversity (educational, functional background, outside industry experience and international exposure) and firm internationalization. We argue that firms with greater TMT diversity will use more international alliances, resulting in higher firm internationalization. Based on a sample of 226 US firms during the period 1988–1994, we find that international alliances partially mediate the relationship between TMT international exposure diversity and firm internationalization. However, we do not find international alliances to mediate the relationships between other forms of TMT diversity and firm internationalization. We discuss implications and directions for future research.     

Accounting for the Value of Performance Measurement from the Perspective of Midwestern Mayors

This article studies the decades-long question, "Does performancemeasurement matter?" by examining how and why Midwest mayorsperceive value in performance measurement. The results showthat the tool is perceived positively, but its impact on decisionmaking depends on whether performance measurement is integratedinto strategic planning, goal setting, and internal communicationbetween city council members and departmental staff and on whethermajor stakeholders are involved in developing performance measures.The article discusses the implications for future results-orientedreforms and concludes that simply reporting performance informationin budgetary or public documents is not enough. Rather, a morecomprehensive look at the implementation issues of performancemeasurement and performance budgeting is necessary.     

Estimation in the bivariate poisson distribution and hypothesis testing concerning independence

Estimation procedures in the bivariate Poisson distribution are briefly reviewed and some errors in the literature are corrected. Asymptotic efficiencies are reexamined for both symmetric and asymmetric cases. Six hypothesis testing procedures, including three studied by Kocherlakota and Kocherlakota (1985), for independence are evaluated by using Monte Carlo simulations.     

Financial-Firm Production of Monetary Services: A Generalized Symmetric Baroett Variable-Profit-Function Approach

An alternative monetary-production model of financial firms is employed to investigate supply-side monetary aggregation. Financial firms are conceived to produce monetary services as outputs through financial intermediation. A new method for testing the existence of consistent monetary-output aggregates in financial firms' production technology is developed in terms of a multiproduct firm's variable profit function, and the method does not require homotheticity of the aggregator function. We use a generalized symmetric Barnett flexible functional form. That specification satisfies global curvature conditions and retains its flexibility under the null hypothesis of weak separability. Neither of those properties is possessed by other flexible functional forms.     

The Effect of Pseudo-Exogenous Instrumental Variables on Hausman Test

Hausman test is popularly used to examine the endogeneity of explanatory variables in a regression model. To derive a well-defined asymptotic distribution of Hausman test, the correlation between the instrumental variables and the error term needs to converge to zero. However, it is possible that there remains considerable correlation in finite samples between the instruments and the error, even though their correlation eventually converges to zero. This article investigates the potential problem that such “pseudo-exogenous” instruments may create. We show that the performance of Hausman test is deteriorated when the instruments are asymptotically exogenous but endogenous in finite samples, through Monte Carlo simulations.     

ENERGY USE AND TEMPERATURE HABITUATION: EVIDENCE FROM HIGH FREQUENCY THERMOSTAT USAGE DATA

Using micro‐level thermostat data from 27,000 U.S. households, we analyze how home heating/cooling decisions respond to weather. Responses are greater for extreme heat than for extreme cold and persist for at least 30 days after exposure, due in part to transaction costs but also to changes in intrinsic preferences. Failure to understand habit can lead us to overestimate the impact of short‐term policy nudges but underestimate the long‐run impact of small changes. Higher frequency estimates of how behavior responds to weather improve our understanding of climate adaptation as climate change affects not only mean temperatures but also variances. (JEL C55, D03, Q4)